Documentation for accessable object properties
The export and import scripts are indeed an excellent form of documentation. 
There is a massive amount of documentation. This includes a quickstart and API overview. More importantly it has a good search box (warning: avoid including parenthesis when searching functions).
Interactively you can use the python console to investigate which properties are available on a given reference. It has a ctrl+space auto-complete (auto reveal).


in the console for instance

&gt;&gt;&gt; obj = bpy.context.object   # the current active object
&gt;&gt;&gt; obj = bpy.data.objects['Cube']   # object specified by name
&gt;&gt;&gt; obj.


if you type obj. and hit ctrl+space you'll see all the attributes of the object at that level. This list is long, and you can scroll the sidebar



As you state me = obj.data, the me named variable is just a convention, it could be called whatever, but it's handy to stick to the convention. 

obj.data.&lt;ctrl+space&gt; looks like



If you want to see information about the mesh you might do

# get coordinates of 1st vertex (index=0)
&gt;&gt;&gt; obj.data.vertices[0].co   

# indices that make up the first polygon in the mesh
&gt;&gt;&gt; obj.data.polygons[0].vertices[:]  




Note that the ctrl+space feature will show all attributes starting with the letter v if you do obj.data.v&lt;ctrl+space&gt; like this:



This becomes useful once you get a mental picture of the API, it can speed up navigation big time.